Allen-Bradley 1771-IFE Analog Input Module
The 1771-IFE senses up to 16 single-ended or 8 differential analog inputs and converts them to a proportional 12 bit binary value. Its use with the EPICS control system supports 3 voltage ranges and 1 current range, selectable on a per channel basis. Supported input ranges include:
Voltages Currents --------------------------------------------------------- 0 to 5V DC (differential) 4 to 20mA (differential) -10 to 10V DC (single ended) -10 to 10V DC (differential)1771-IFE Analog Input Module Strapping
Remove the module's left hand cover plate (the one without the labels). Observe the location of the configuration jumpers in figure 5.1, and note the location of the individual channels. The input range is determined in software, however the single-ended or differential determination, as well as the type of input, voltage or current, is configured by the above jumpers. figure 5.2 contains diagrams detailing this information. Refer to figure 5.1 for channel clarification.
1771-IFE Analog Input Module Installation
The Allen-Bradley 1771-IFE Analog Input Module may be installed in any Allen-Bradley Universal I/O Chassis, 1771-A1B, 1771-A2B, 1771-A3B, or 1771-A4B. Before Installation, calculate the power requirements of the modules currently in the chassis. Add to that 750mA @ 5V DC, the current required by the 1771-IFE. Check to be sure that this combined current requirement does not exceed the current driving ability of the chassis power supply.
Module Location in the I/O Chassis
The 1771-IFE may be placed in any slot of the I/O chassis with the exception of of the extreme left slot. This slot is occupied by the Remote I/O Adapter Module. It is suggested that analog input modules and low voltage DC modules be placed away from AC modules or high voltage DC modules to minimize electrical noise interference.
The Allen Bradley Universal I/O chassis have the ability to limit the slot access to certain modules by the implementation of a keying system. Modules are slotted in two places at the edge of the circuit board. The position of the keying bands on the backplane connector of the I/O chassis must correspond to these slots. To key a slot for use by the 1771-IFE Analog Input only, place the keying bands between 10 and 12 and between 24 and 26 on the I/O chassis backplane connector.
Before a module is inserted into the Universal I/O Chassis, be sure that the power to the chassis is shut off. This can be done without shutting off the IOC that the Universal I/O Chassis is connected to, and without removing the subnet communication link. To insert the module, place it in the plastic tracks on the top and bottom of the Universal I/O Chassis. Slide the module into the Universal I/O Chassis until the module comes in contact with the backplane connector. Do not force the module in, instead apply firm and even pressure on the module to seat it properly on the backplane connector. Snap the chassis latch over the top of the module and connect the wiring arm to the module. The Universal I/O Chassis should begin communicating with the host IOC when power is reapplied, no rebooting of the IOC will have to be done.
1771-IFE Analog Input Module Wiring Connection
Connection of analog signals to the 1771-IFE is accomplished through the use of the wiring arm. Signals should be connected to the screw terminals on the wiring arm, as detailed in figure 5.3, and the wiring arm should be connected to the front tab connector on the 1771-IFE. The recommend cable length for voltage signals is 50ft. This is based on considerations of signal degradation and electrical noise immunity in typical industrial environments. When shielded cable is used and grounding of the shield is desired, it is recommended that the connection be made at one of the I/O chassis mounting bolts. To prevent ground loops only one end of the cable shield should be grounded.
1771-IFE Analog Input Module Use
The front panel of the 1771-IFE contains a green RUN and a red FAULT indicator. At power up an initial module self-check occurs. If there is no fault the red indicator will turn off. The green indicator will flash until the processor communicates successfully with the module.